Why does Ramotswe feel scared about visiting Ranta and how does Matekoni help her?

Ramotswe is fearful of going to Dr. Ranta's house alone. Mr. J.L.B. Matekoni sensed she was troubled when he came to dinner. He had been to the prison to visit Florence and told Mma Ramotswe about it. When she tells him about visiting Dr. Ranta, she refers to him as a psychopath. Mr. J.L.B. Maketoni says he will accompany her to Dr. Ranta's house. He does not want her to go alone.